The main purpose of the proposed research is to characterize the relationship between syntax and semantics during sentence processing. We propose seven experiments, which use ambiguous words and sentences, to investigate the effects of prior syntactic and semantic context on the access of meaning from the mental lexicon. It is anticipated that these experiments will provide evidence for an on-line serial model of sentence processing in which either prior syntactic or semantic cues can restrict lexical access. That is, syntax, semantics and the lexicon can be viewed as autonomous components which interact at the word level during sentence processing. Our experiments also address the question of how the lexicon is organized by demonstrating that there are several vehicles that can be used to access information in the lexicon. Specifically, we expect to show that a particular meaning can be accessed through syntactic channels (i.e., by knowledge of the syntactic category) and through semantic channels (i.e., by semantically related meanings) in addition to orthographic and phonological channels.